Introduction: A better understanding of molecular mechanisms of oral squamous cell carcinoma (OSCC) and identification of potential oncogenes may provide new therapeutic decisions such as targeted therapy. Most of the studies suggest that OSCCs expressing Epidermal growth factor receptor (EGFR) display pathological features of more aggressive tumors and its overexpression is associated with poor prognosis.1 Studies have also shown that the overexpression of HER2/neu increased metastatic potential and that cell proliferation, as measured by the Ki67 labelling index at the invasive tumor front is directly related to the histological grade in OSCC.2,3 Objectives: To study the expression of EGFR and HER2/neu in oral mucosal dysplasia and SCC, to evaluate their correlation, to compare their expression in different histological grades of the tumor, to evaluate the relationship between their expression and tumor proliferation index demonstrated by Ki67 labelling with an aim of emphasizing the role of these biomarkers in oral carcinogenesis as well as their role as potential therapeutic target. Materials and methods: This study was conducted on 68 patients having oral dysplasia or SCC. Immunohistochemistry was done for EGFR, HER2/neu and Ki67 and their expression was evaluated under the microscope. Results: EGFR overexpression is associated with higher grades and poorly differentiated tumors. Expression of EGFR is also more in superficial layer in higher grades of dysplasia. There is statistically significant difference in EGFR expression between cases of dysplasia and OSCC. However no such correlation was found with respect to HER2 expression. Conclusions: We conclude that EGFR overexpression is associated with higher grades and higher intrinsic proliferative activity. Hence EGFR can serve as a good prognostic indicator and a target for anticancer therapy. However no similar role of HER2 could be proved.

Keywords: EGFR; HER2/neu; Ki67; Oral dysplastic epithelium; Oral squamous cell carcinoma.